INSAT-2D almost dead, says scientists
D Jose in Thiruvananthapuram
India’s INSAT-2D communication satellite is almost dead, scientists at the Indian Space Research Organisation, Bangalore, said on Friday night. The satellite, launched on June 4, was crippled by a serious power problem.
Scientists at the Vikram Sarabhai Space Centre, who were associated with the satellite's development, said the extreme step would have to be taken if the power problem that crippled its key functioning cannot be rectified quickly. But as of now they have little hope of reviving the $ 50 million AR 2079 kg satellite.
Sources at ISRO, Bangalore, said agency chairman K Kasturirangan and other senior scientists discussed the crisis and considered alternative strategies. The power failure happened after the one of power buses, the units supplying power to subsystems of the spacecraft, failed. The resultant loss of communication with earth disrupted functioning at the National Stock Exchange and affected the Unit Trust of India and Standard Chartered Bank.
But UTI had only begun its trial run last week while Standard Chartered used a low-end satellite as a backup, has three links on another satellite and another four submarine lines to its Singapore office.
Though three transponders belonging to private VSAT operators have been partially revived, even these are unlikely to last long, the scientists said. The remaining power bus is taking the strain now. It might not be able to keep going for very long, the scientists said, without specifying any time frame.
The NSE had recently shifted part of its networking from the drifting INSAT-1A satellite to INSAT-2D. INSAT-1A kept drifting from course, affecting communication at times. The NSE used only three of the 24 transponders aboard INSAT-2D. The others were not loaded yet. None of the revived transponders belonged to the NSE. Doordarshan officials said the snag was unlikely to affect its functioning.
ISRO sources said the power may have been lost due to a short circuit caused by loss of insulation, itself caused by an electrical discharge in the power circuit. The ISRO management is working on minimising the disruption of the satellite's services by shifting its operational links to other Indian satellites like INSAT-2C, INSAT-2B and INSAT-2A.
The next satellite, INSAT-2E, is scheduled to be launched only next June.
INSAT-2D's transponders were meant to introduce additional television channels and improve the communication networks. It has 12 transponders to beam television signals over the sub-continent and six high-power transponders for wider coverage, from Southeast Asia to the Middle East.
Launched by an Ariane flight from Kourou in French Guyana on June 4, the satellite is in the same orbit as INSAT 2A at 74 degrees east.
Coming in the wake of this week's snag that affected the Polar Satellite Launch Vehicle, the current problems have put the Indian satellite placement programme under a cloud. The defect -- a leak in the fourth stage of the rocket -- caused the IRS-1D satellite to be placed in a life-shortening elliptical orbit instead of the expected circular one. The scientists were still grappling with that problem when INSAT-2D failed. INSAT-1C, launched on July 21, 1988, had to be abandoned in November 1989.
The problems have come up at a time when the government has decided to open up transponders to the private sector and when it was striking a deal with other countries to launch satellites for them. ISRO had already signed an agreement to lease 11 transponders to the International Telecommunication Satellite Organisation.
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